What is the ruling on a mother's action of donating her disobedient son's share to his two brothers? And do the two sisters have the right to retract their donation after 17 years? And is the financial reconciliation for the eldest brother sufficient Islamically despite his current retraction?

First: A father's bequest of half the dwelling to the mother is impermissible without the consent of all heirs, and your eldest brother had the right to object.

Second: Your mother erred in preferring some of her children over others in the gift; fairness among them was obligatory.

Third: Your reconciliation with your brother was a good deed. As long as he accepted and was content, he has no right to demand anything now.

Fourth: If your sisters relinquished their right willingly and they are mature, they cannot retract their decision, because a gift becomes binding upon possession, and it is forbidden to revoke it.